Rep. Bill Shuster (Pa.) directed a part-time aide on his Congressional payroll to conduct surveillance of his GOP primary opponent, the former staff member charged in an open letter circulated Wednesday on the Internet.

Joshua Juda, an Altoona, Pa., resident who worked in Shuster’s district office, said he was directed by Shuster and the lawmaker’s top aide to monitor the home and daily activity of Michael DelGrosso, the 33-year-old challenger whose family operates a spaghetti sauce company.

Juda, who worked 25 hours a week on Shuster’s staff, said he resigned Oct. 31. House records show he was paid $3,000 in the second quarter of this year.

Alex Mistri, Shuster’s chief of staff, acknowledged that Juda had been monitoring DelGrosso but denied that taxpayers funded the operation.

“Politics on government time is prohibited in the office of Congressman Shuster,” Mistri said in a statement. “As Chief of Staff, I strictly enforce this. There was not one penny of taxpayer money spent on this incident. Anything said to the contrary is false.”

Juda, who did not return phone calls left at his home, said in his letter that he was directed to monitor a DelGrosso fundraiser on June 6 and inform Shuster and other staff members about the event’s attendees. Juda said he was then directed to observe DelGrosso’s home in Tipton, Pa., on Sept. 10 and 12 and report on DelGrosso’s daily activities.

“At each occasion, it was my understanding that I was functioning in my capacity as a congressional staff member for which I was being paid through the Congressional payroll. I was not employed by any other outside organization or internal division of Congressman Shuster’s office. I never functioned as a volunteer for the 2004 Shuster Campaign. I was never therefore reprimanded or discouraged from such activity. I was never asked to serve in anyway without pay or as a volunteer outside of my part-time capacity and it was my understanding that all of my activities were covered within my allotted 25 hours per week,” Juda said.

After a DelGrosso neighbor who observed Juda’s surveillance filed a report with the state police, Shuster instructed Juda not to say anything about his activity, the former staffer said. “Further requests were made of me not to use office phones or unsecured lines that could link my observation activities to my official capacity as a congressional staff member,” Juda wrote.

DelGrosso has criticized Shuster as someone who was handed a Congressional seat by his father, former Rep. Bud Shuster (R-Pa.), the powerful Transportation and Infrastructure chairman who resigned from the House shortly after being reprimanded for ethical misdeeds.

“If this is true, then the implications are very serious,” DelGrosso said of the accusations, noting that House ethics rules prohibit Congressional staffers from performing campaign work on government time.