SANFORD, Florida (Reuters) - George Zimmerman, the neighborhood watch volunteer charged in the Florida killing of unarmed black teenager Trayvon Martin, returned to jail on Sunday after a court revoked his bond and ordered him back into custody.

Zimmerman, who had been free on a $150,000 bond and hiding in an undisclosed location, arrived at the Sanford County jail in a white police mini-van shortly before the 48-hour deadline imposed by Circuit Court Judge Kenneth Lester Jr. on Friday.

The 28-year-old Zimmerman, dressed in jeans and a plaid shirt and accompanied by Seminole County Sheriff's deputies and his attorney, Mark O'Mara, walked into the jailhouse with his hands cuffed behind his back.

Zimmerman did not respond to shouts from media outside.

O'Mara told reporters Zimmerman was "frustrated" at having to return to jail and that "he has a real concern for his safety any time he has to come out of hiding."

It was the latest twist in a murder case that has captured global media attention and sparked widespread debate in the United States over guns, self-defense laws and race relations.

Zimmerman, who is white and Hispanic, is charged with fatally shooting 17-year-old Martin on Feb 26. as the teenager walked through a gated community in Sanford where he was staying with his father.

Police initially declined to arrest Zimmerman, citing Florida's "Stand Your Ground" self-defense law, but six weeks later a special prosecutor charged him with second-degree murder. Zimmerman has pleaded not guilty and said he fired in self-defense after Martin broke his nose and bashed his head on a side-walk.

On Friday Judge Lester revoked Zimmerman's bond, posted in April while he was awaiting trial, after prosecutors said he had withheld one of two valid passports and his wife did not tell the court about money donated for his legal defense.

Zimmerman returned to Central Florida, arriving late Saturday evening, O'Mara announced earlier on Sunday in an online statement.

SEGREGATED FROM OTHER PRISONERS

Seminole County Sheriff Don Eslinger told reporters that Zimmerman surrendered in a rendezvous in a business parking lot a few miles away in Lake Mary, near Orlando.

Zimmerman will be housed in administrative confinement, segregated from the general prison population, "due to the high profile nature of the case," the Sheriff's office said.

In a defense team statement on Sunday, O'Mara said he planned to seek a new bond hearing and hoped his client's voluntary surrender "will help demonstrate to the court that he is not a flight risk."

O'Mara indicated to reporters outside the jail that his client may have acted unwisely in regards to his passports and the defense fund. "He (Zimmerman) understands the court's concern now we've had a chance to look at it," he said.

O'Mara said he believes judge Lester will want to question Zimmerman and his wife Shelly before he will consider granting bond again.

But he said he was undecided whether allowing Zimmerman to testify in a bond hearing would be wise, and acknowledged his client has a credibility problem after alleged jailhouse phone calls with his wife in which the prosecution says the couple conspired to hide the passport and money from the court.

"It's a question of credibility with Mr Zimmerman and that credibility has been attacked or tarnished and, now that has to be rehabilitated," O'Mara said.

Asked by Reuters whether Zimmerman has an explanation for the phone transcripts that differed from the prosecutors' interpretation, O'Mara said, "I think that the explanation or apology, if it is, should go to that person (the judge)."

He would not speculate about whether Zimmerman's wife might be charged with perjury. "I believe she'll have counsel," he said. Zimmerman was "very worried about Shelly, about a lot of issues," he added.

In the earlier statement on Sunday, O'Mara noted that Zimmerman had waived his right to speedy trial on May 8, meaning he could face a long wait in jail. "It is anticipated, though not certain, that the case will not be ready for trial until some time into 2013."

RECORDED CALLS

Zimmerman's whereabouts were unknown during the weeks following his release after spending 11 nights in April in a Sanford jail cell. His lawyer declined to discuss his location or living arrangements, citing death threats and fears about Zimmerman's security.

Prosecutors alleged in court on Friday that his wife knew about donations for his legal defense fund, now totaling in excess of $200,000, but she failed to disclose the money at his bond hearing.

"The defendant's wife lied to this court," prosecutor Bernardo de la Rionda told the judge.

The motion to revoke Zimmerman's bond cited phone calls made to his wife from jail in which Zimmerman instructed his wife in coded language to transfer money into her personal account.

When Zimmerman surrendered his passport at his April 20 bond hearing, he did so knowing that he had a second unexpired passport, the prosecution also alleged.

In one recorded phone call from jail, the motion said Zimmerman told his wife he thought the passport was in a bag and she replied, "I have one for you in a safety deposit box."

"OK, you hold onto that," Zimmerman allegedly told her.