Florida judge has ruled that George Zimmerman can be freed from jail to await his trial for the murder of 17-year-old Trayvon Martin.

But a in a hard-hitting written decision that increased his bail to $1m, circuit court judge Kenneth Lester said the neighbourhood watch captain and his wife had tried to deceive the court by lying about their personal finances, and took a swipe at his lawyer Mark O'Mara for trying to portray Zimmerman, 28, as young and naïve.

"Trayvon Martin is the only male whose youth is relevant to this case," Lester wrote. "Counsel attempted to portray the defendant as being a confused young man who was fearful and experienced a moment of weakness and who may also have acted out of a sense of 'betrayal' by the system. Based upon all the evidence, the court finds the opposite."

Lester also noted that Zimmerman's story had changed several times and said that he considered him to be a flight risk if bail was set at a lesser amount.

Zimmerman, who shot and killed the unarmed Martin, 17, in a confrontation in a Sanford gated community on 26 February but denies second-degree murder on the grounds of self-defence, was initially freed on $150,000 bail in April.

He returned to jail on June 3 when Lester revoked his bond following claims from prosecutors that Zimmerman "hid" more than $135,000 in public donations to a website he set up in the aftermath of the killing. The court heard that he shifted tens of thousands of dollars into the account of his wife Shellie, who then testified that the couple was virtually penniless. Shellie Zimmerman, 25, has since been charged with perjury.

"Under any definition, the defendant has flaunted the system," the judge said in his ruling. "Contrary to the image presented by the defendant not by evidence but only by argument of counsel, it appears to this court that the defendant is manipulating the system to his own benefit. The evidence is clear the defendant and his wife acted in concert, but primarily at the defendant's direction, to conceal their cash holdings."

Judge Lester said that Zimmerman, who had taken courses in becoming a police officer, and had been arrested previously, "had a very sophisticated knowledge of the criminal justice system over and above that of the average, law-abiding citizen".

The judge's decision came six days after a fiery bail hearing at which Zimmerman turned down an opportunity to take the stand and apologise in person for deceiving the court because it would have meant opening himself to cross-examination.

Zimmerman must pay 10% of the set bail to secure his freedom, and he was expected to walk out of Sanford's John E Polk correctional facility later within the next two days.

"The increased bail is not a punishment," Lester wrote. "It is meant to allay the court's concern that the defendant intended to flee the jurisdiction, and a lesser amount would not ensure his presence in court."

Among the terms of bail are that Zimmerman must not enter the property of the Orlando-Sanford international airport, must not open or maintain a bank account, cannot drink alcohol and must check in every other day with the court's pre-trial release programme.

Additionally, he must wear a tracking ankle bracelet at his own expense, and not apply for or obtain a passport.

At last Friday's hearing, O'Mara had asked for leniency from the court and for bail to be reinstated at $150,000. He also called Zimmerman's father Robert, a retired magistrate, to testify for him, and presented much of the medical evidence he expects to rely on at trial to try to prove that Martin was the aggressor during the fatal incident.

Prosecutor Bernie de la Rionda wanted Zimmerman to remain in jail until his trial, which is not expected to take place until at least the middle of next year. He would be jailed for at least 25 years if convicted.

In the meanwhile, O'Mara is expected to file a motion to have the case dismissed under Florida's controversial stand-your-ground law, which allows for the use of deadly force if a person feels his life is in danger.

Zimmerman claims his nose was broken and he suffered head injuries during a scuffle initiated by his victim, and that he pulled the trigger for self-preservation.