Meanwhile, Norway said its suspicion that a Norwegian citizen was one of those involved in the mall assault claimed by the Somali Islamist group Al Shabaab had now strengthened after the BBC identified one of the attackers as a 23-year-old Norwegian citizen of Somali origin named Hassan Abdi Dhuhulow.
A Western official close to the investigation confirmed Dhuhulow's name was among those investigators were looking at.
Ndung'u Gethenji, head of the Kenyan parliament's Defence and Foreign Relations Committee, said the corpses had been pulled from under rubble on Thursday in a part of the mall which had collapsed.
He said: "All the indications are that they are the attackers, the site they were excavating is consistent with the area [the gunmen] were trapped in during the operation."
Automatic AK-47 rifles of a model not used by Kenyan security forces and a rocket-propelled grenade were found close to the two bodies, added Mr Gethenji, who is also co-chairing a parliamentary investigation into possible intelligence failures.
Dramatic CCTV footage emerged earlier this week showing the first day of the four-day stand-off with Kenyan security forces.
It shows four gunmen calmly shooting panicking shoppers as others hid behind pillars or scramble along the floor towards exits.
At one point, a gunman walks up to a wounded man bleeding heavily as he tries to pull himself to safety and shoots him at close range, apparently killing him.
The attackers are also seen taking turns to pray in what looks to be a store room.
Almost a month after the Westgate attack, Mr Gethenji said it was still unclear if more gunmen than the four seen in the CCTV footage had been involved in the attacks.
Kenyan authorities initially said up to 15 militants took part in the assault with automatic weapons and grenades, but Mr Gethenji said six was more likely. The MP said the corpses of the two suspected gunmen will now be subjected to detailed forensic investigations.
Norway's police security service, PST, has declined to confirm or deny Dhuhulow was one of the attackers.
Former classmates at the high school he attended in the small Norwegian town of Larvik, about 80 miles south of the capital Oslo, recalled Dhuhulow as a deeply religious teenager who took his prayer mat to school each day.
"He was a little weird and usually stayed under the radar," one classmate at the Thor Heyerdahl school said. Another contemporary said Dhuhulow had openly supported the killing of US troops on foreign battlefields.
The classmate added: "He became very religious in the period between middle school and high school and was very conservative."
Al Shabaab have said they carried out the mall attack because the Kenyan government had ignored its warnings to pull peacekeeping troops out of Somalia.
Uganda, which also has troops in Somalia, warned yesterday of a possible "imminent terror attack" on its territory.