Rajapaksa was the Prime Minister at the time in 2005 when the case was heard.
The convener of Lawyers United, Chandrapala Kumarage, told the BBC Sinhala Service Sandeshaya that a pronouncement made by the former Chief Justice Sarath N Silva that he (Silva) should apologise to the country and people for the court ruling that went in favour of Rajapaksa, was enough proof that there had been wrongdoing in the handling of funds deposited for the Helping Hambantota project.
Silva made the announcement in an interview with Sandeshaya last October.
"The fact that he apologised meant that there was something wrong", Kumarage.told Sandeshaya in the interview.
Kumarage said that it was a crime for funds meant for public welfare to end up in the private account of an individual, in this case Mahinda Rajapaksa.
"There is enough grounds and no barrier to open the case again", Kumarage told Saroj Pathirana who interviewed him from the BBC's Sinhala Service Sandeshaya.
He added that a past murder case involving former MP Chandana Kathriarachchi and another against MP Duminda Silva over corruption were also possible to be reopened.
Efforts by srilankamirror to contact Justice Minister Wijedasa Rajapaksa for his reaction proved futile.