The two leaders, both Rajya Sabha members, have allegedly been named by three Bharatiya Janata Party members of Parliament in their complaint before Lok Sabha Speaker Somnath Chatterjee. Both Singh and Patel have denied any involvement.
"The process of recording evidence is complete," senior Congress member V Kishore Chandra Deo, who is heading the committee, told reporters after a three-hour hearing on Monday.
Asked whether Singh and Patel would be called for questioning, Deo parried a direct reply saying there were no plans as of now to call any more witness.
On when the panel will submit its report, he said "as soon as possible. We will meet soon, may be within a week and try our best to give the report by August 29, (the day the committee's term expires)."
During Monday's hearing, SP member Reoti Raman Singh, BJP activist Sudheendra Kulkarni, Amar Singh's reported aide Sanjeev Saxena and one Suhail Hindustani, who was seen in the CD released by CNN-IBN which conducted the sting operation, deposed.
After deposing before the committee, Kulkarni told media-persons he had assisted in the whistle-blowing operation. "If an impartial inquiry is held, the truth will come out and Amar Singh will be found guilty," he claimed adding that he, however, did not doubt the impartiality of the panel.
He also said he had given evidences before the panel in support of his contention.