Washington- Indictments in the CIA leak investigation case are expected to be handed down by a grand jury on Wednesday, bringing to a head a criminal inquiry that threatens to disrupt seriously President George W. Bush’s second term.

On Tuesday night, news reports, supported by a source close to the lawyers involved in the case, said that target letters to those facing indictment were being issued, with sealed indictments to be filed on Wednesday and released by the end of the week.

Those in legal jeopardy may include Lewis “Scooter” Libby, vice-president Dick Cheney’s chief of staff, and Karl Rove, Mr Bush’s chief political strategist.

Mr Cheney himself has also been linked to the inquiry into the leaking of the name of an undercover CIA operative, according to a story in Tuesday’s New York Times.

Patrick Fitzgerald, special prosecutor, has said he would announce any conclusion to his 22-month investigation in Washington.

The New York Times report said Mr Cheney had talked with Mr Libby on June 12 2003 about the fact that the wife of former ambassador Joseph Wilson, a critic of the administration’s claims about Iraq, worked at the agency. The identity of his wife, Valerie Plame, was first disclosed by Robert Novak in an syndicated column on July 14 2003, which triggered the inquiry.

The suggestion appears to contradict comments in late 2003 from Mr Cheney that he did not know who had sent Mr Wilson to Niger in February 2002 to investigate claims that Saddam Hussein was trying to buy uranium. They also cast some doubt on statements Mr Libby is reported to have made to the grand jury that he may have learned about Ms Plame’s job from journalists.

On Tuesday Scott McClellan, White House spokesman, declined to comment on the reports about Mr Cheney. He came under fire again for his own denials in 2003 that White House officials had played no role in leaking the name of Ms Plame. Robert Luskin, Mr Rove’s lawyer, declined to comment on whether his client had received a letter. A spokeswoman for Mr Cheney also declined to comment. Mr Rove and Mr Libby have continued to play an active role in advising the president. Mr Libby was part of the committee that picked Ben Bernanke as the president’s nominee for chairman of the Federal Reserve.

Mr Rove is involved in shoring up the beleaguered nomination of Harriet Miers to the Supreme Court.

Mr Bush has praised Mr Fitzgerald’s deft handling of the inquiry, which could deflate any later attempts to paint him as a partisan prosecutor over-reaching his mandate.

However, Frank Luntz, Republican pollster and strategist. said: “If [Fitzgerald] indicts, they [the White House] will have no choice but to attempt to demonise him. I think that is going to be really, really tough.”