Two years ago, when Mubin Shaikh first went public with his tale of anti-terror espionage, he was candid about his compensation. He told Canadians the RCMP paid him a cool $300,000 to spy on the "Toronto 18," a group of young, tough-talking Muslims who liked to camp in the snow (and allegedly plot jihad). But Shaikh insisted, over and over, that cash was not his motivation. He went undercover to protect his country and his religion, not to line his pockets. "I didn't do it for the money," he said shortly after the arrests. "I'm not going to negotiate with the lives of Canadians."

Today, Mubin Shaikh is ready to negotiate. Canada's most famous informant — the public face of the nation's largest-ever terrorism trial — is asking for a $2.4-million raise.

In a two-page letter addressed to the Mounties, Shaikh vows to abide by a long list of conditions in exchange for the hefty, "no tax" payment ($2.7 million, minus the $300,000 he's already received). His promises include no more media interviews, no more drug use, and no book or movie deals. The 32-year-old also pledges to "aggressively defend the evidence and vocally support the role of the agencies involved" in the case, including the RCMP and CSIS, Canada's spy agency. "This document is intended to be a formal request for further compensation that is 'deserved and proportional' to my involvement" in the investigation, Shaikh writes.

The note contains no explicit threats. Shaikh, a married father of five, does not go so far as to say he will abandon the case if the cops don't cave. However, one of his proposed conditions is a promise not to "bring any legal action against the RCMP/CSIS."

The authorities have yet to respond to Shaikh's letter, but this much appears certain: police and prosecutors are growing increasingly impatient with their prized informant. The timing of his extravagant demand was especially bold. Shaikh sent his note to the Mounties on June 9, just days before his widely publicized testimony at the trial of a teenager charged in connection with the bust. "It certainly makes a mockery of his 'I'm not doing this for the money' line," says lawyer Michael Moon, who represents Steven Chand, one of 10 adults still facing charges. "The Crown's devout, patriotic witness keeps on upping his price, depending on what trial he's at."

Indeed, this is the second time Shaikh has requested a pay hike. In the early stages of the investigation, he happily accepted $77,000 to infiltrate the group. He bugged his minivan, befriended one of the alleged leaders, and famously joined the suspects on a two-week winter camping trip that prosecutors now believe was the genesis of a sophisticated plot to detonate truck bombs in downtown Toronto. But in June 2006, days after the high-profile raids, Shaikh went back to the RCMP and asked them to boost his reward to an even $300,000. They agreed.

Two years later, it's hard to imagine a repeat outcome. Despite his undeniable charm and outspoken disdain for aspiring terrorists, Shaikh is proving to be as much of a Crown liability as an asset. As star witnesses go, he has become more star than witness. Since the arrests, he has outed himself on national TV, proclaimed the innocence of some of the accused, snorted cocaine on the taxpayers' dime, and pleaded guilty to threatening two 12-year-old girls. During his recent testimony at the youth trial, he also sparred with prosecutor John Neander, who took the rare step of declaring Shaikh a hostile witness and grilling him on some alleged inconsistencies in his statements. Simply put, the Crown accused its own hired mole of fudging facts to protect the defendant. A few days later, Shaikh went one step further, telling reporters the teenage suspect deserves to be acquitted.

And now, after all that, Mubin Shaikh wants more cash — more than 30 times the dollar figure he originally agreed to. "You have to be concerned about the motives of an informant whose sole source of income has been taxpayer money," says defence lawyer Dennis Edney, whose client, Fahim Ahmad, faces more charges than any of the accused. "And if Mr. Shaikh is asking for more money, then it causes further concern that his sole motivation in giving evidence is financial rewards."

This case, of course, already has a controversial history of financial rewards. A second informant, an unidentified businessman who is now hiding in the witness protection program, was paid at least $4.1 million for his covert assistance — and only after the Mounties talked him down from his original offer of $15 million. At the time, Shaikh had no idea the other spy existed, let alone the fact he was being paid millions of dollars. After the raids, when he did find out, Shaikh claimed to have no regrets. "I've got no complaints," he said in February 2007. "I'm not thinking: 'Oh damn, I should have asked them for more.' Nope. I'm happy with everything."