Washington ? The Justice Department on Tuesday won its first trial in the probe of influence peddler Jack Abramoff, convicting a former Bush administration official in a case that touched on questionable behavior by members of Congress.

A jury found David Safavian had hidden details of his relationship with Abramoff from a General Services Administration ethics lawyer, the GSA’s Inspector General’s office and the Senate Indian Affairs Committee and had obstructed the IG.

Safavian, the GSA’s former chief of staff, could face up to five years in prison on each of those four counts. He was acquitted of obstructing the Senate probe.

The guilty verdict is expected to give a boost to a wide-ranging federal investigation that includes lawmakers, their aides and members of the Bush administration.

In Miami, meanwhile, a judge granted Abramoff and ex-business partner Adam Kidan another three months before they must begin serving prison sentences for fraud convictions stemming from the purchase of a gambling boat fleet. Abramoff also faces sentencing in Washington on federal charges of conspiracy, tax evasion and mail fraud.

The delay will give the two more time to cooperate with investigators.

In persuading a jury to convict Safavian, prosecutors introduced a photograph of Rep. Bob Ney, R-Ohio, and Abramoff standing next to a private jet that whisked them and other members of a golfing party to Scotland for five days at the storied St. Andrews Old Course. Safavian was in the photo too, as were two of Ney’s aides who also went on the Abramoff-organized junket.

Recent Justice Department court papers say Ney engaged in 16 actions on behalf of Abramoff at the same time the congressman and his staff were accepting gifts from the lobbyist.

In response to Tuesday’s verdict, Ney’s office blamed Ney’s problems on “the lies and deception of Jack Abramoff.”

Ney “has never, at any point, engaged in any improper, unethical or illegal activity” and the Safavian case “had absolutely nothing to do with Congressman Ney,” his office said.

Prosecutors never called Abramoff to testify, instead relying on e-mail traffic to detail the relationship between the lobbyist and Safavian.

Abramoff, the e-mails showed, showered the GSA chief of staff with the lobbyist’s largesse while badgering him for information about two pieces of government-controlled property the lobbyist wanted. One of them was the historic Old Post Office in downtown Washington.

Safavian’s sentencing was scheduled for Oct. 12.