DRPA sent letters this week to Lawless and Joyce, seeking the return of laptops, cell phones, and other DRPA-owned equipment.
The request was made to preserve information about E-ZPass use in response to the attorney general's subpoena, the letters said.
Matheussen denied television news reports that the FBI or other federal agencies also had sought information from DRPA.
"I'm not aware of any inquiries from any federal authority," Matheussen said Friday.
A knowledgeable federal source said the FBI was not currently investigating DRPA.
The Attorney General's Office issued its subpoenas about three weeks ago, and the state comptroller issued more this week, Matheussen said. Spokesmen for the two offices declined to comment on the nature or scope of the investigations.
Joyce resigned from DRPA after revelations that he had borrowed an E-ZPass from Lawless in 2008 to provide free river crossings for his daughter to attend school in Lower Merion. At the time, DRPA provided free bridge crossings or PATCO rides to all employees and retirees.
In the face of public criticism of that and other perks for DRPA managers, the agency's board on Wednesday voted to eliminate the free crossings, as well as car allowances for 11 DRPA executives.
Two DRPA employee unions - the Fraternal Order of Police and the Operating Engineers - have formally objected to elimination of the free crossings because the benefit was included in their negotiated contracts.
The E-ZPass issue is one of many that have engulfed the politically connected bistate agency in the last month, prompting Gov. Christie and Gov. Rendell to demand broad changes to make DRPA more open and less susceptible to political influence.
On Wednesday, the DRPA board responded by approving 17 measures that would end closed-door meetings, limit no-bid contracts, end economic-development spending, and ban hiring of employees' relatives, among other reforms. Seven additional measures will be taken up at a special board meeting Wednesday.
Also Friday, board member and Philadelphia labor leader John J. Dougherty renewed his call for the dismissal of Matheussen and DRPA general counsel Richard Brown.
In a letter to DRPA chairman John Estey and vice chairman Jeff Nash, Dougherty said Matheussen "has lost credibility through his mismanagement of the authority and must be replaced." At Wednesday's board meeting, he said, Brown made "rambling responses to important questions" and misstated the number of lawyers employed by the agency.
Contact staff writer Paul Nussbaum at 215-854-4587 or pnussbaum@phillynews.com.
Inquirer staff writer John Shiffman contributed to this article.
