Washington, Oct 30 : A leading NASA scientist, credited with helping discover water on the Moon on India's Chandrayaan mission, who has been arrested on charges of spying for Israel was denied bail after prosecutors said he was a "walking safe deposit box" of government secrets.

Judge Deborah Robinson Thursday rejected a bail request from Stewart David Nozette, who was arrested in an Oct 18 sting operation, saying he was considered too much of a flight risk and should remain in jail pending trial.

Nozette, 52, pleaded not guilty to charges that he tried to sell US defence secrets to an undercover FBI agent who was posing as an Israeli intelligence officer for $2 million. The Justice Department could seek the death penalty.

Nozette, who had high-level security clearances worked at the US space agency NASA, the Energy Department, and even served on the White House's National Space Council in 1989 and
1990, under then president George H. W. Bush.

He was one of the main investigators of an American scientific instrument that flew aboard India's lunar craft Chandrayaan-1. His biography described him as the instrument's principal investigator on the American Lunar Reconnaissance Orbiter and Co-investigator on Mini-SAR on Chandrayaan-1.

The Mini-RF (Radio Frequency) project flew two radar instruments - the first one on ISRO's Chandrayaan called Mini-Sar (synthetic aperture radar), which mapped lunar poles, and the second one on NASA's Lunar Reconnaissance Orbiter.

The American space agency had put another instrument on the Indian lunar probe, Moon Mineralogy Mapper, which effectively proved the presence of water molecules on the moon's surface.

Nozette was known primarily as a defence technologist who had worked on the Reagan-era Star Wars missile shield effort formally named the Strategic Defence Initiative.

Because he knows so many secrets, including about the nation's nuclear missile programme, Attorney General Eric Holder has ordered special communications restrictions placed on him while he's in jail, authorities said.

"The defendant is himself a walking safe deposit box of classified information," said prosecutor Anthony Asuncion. "He is now a treasure trove of some of our most sensitive matters."

Nozette's attorney argued that his client did not pose a flight risk. He was charged only with attempted espionage and did not have ties to foreign intelligence services, Nozette's lawyer John Kiyonaga said.

According to prosecutors, Nozette was paid more than $225,000 by a company that was wholly owned by the Israeli government and spoke to them regularly. In court Thursday, Kiyonaga identified the company as Israel Aircraft Industries.

During one of his secretly recorded conversations with the undercover FBI agent posing as an Israeli intelligence officer, Nozette said: "I thought I was working for you already. I mean, that's what I always thought, (the foreign company) was just a front."

Court documents from the prosecution alleged Nozette, "delivered and communicated this classified information to an individual he believed was an Israeli intelligence officer in exchange for an alias, a foreign passport, and cash payments", they said.

In their final discussion, the undercover FBI agent allegedly handed Nozette $10,000 in 100 dollar bills, which he tried to hide inside a hotel bathroom toilet tank when federal agents arrested him.

The FBI also searched Nozette's safe deposit box at a bank in San Diego, California, where they discovered 55 gold "Krugerrand" coins worth a total of $50,000 and $30,000 in savings bonds, court documents said.(IANS)