They include Kazakhstan's Ilya Ilyin, a four-time world champion who also won gold in the 94kg category at the Beijing Games in 2008.
The others are Kazakhstan trio Zulfiya Chinshanlo (53kg), Maiya Maneza (63kg) and Svetlana Podobedova (75kg).
If all four are disqualified, Kazakhstan would drop from 12th to 23rd in the 2012 medal standings.
Six other lifters who competed at the 2012 Games also tested positive after hundreds of samples were reanalysed.
Among them are Russia's Apti Aukhadov, who won silver at 85kgs, Ukraine's Yuliya Kalina, who took bronze at 58kgs, and Belarusian Marina Shkermankova, who won bronze at 69kgs.
Completing the group of doping positives are Azerbaijan's Boyanka Kostova and Belarus duo Dzina Sazanavets and Yauheni Zharnasek.

The high jumper won bronze in 2008 but that result is now in doubt after 454 samples from those Games were retested.
"It's the most complete shock," said Chicherova, who went on to win gold at the 2012 Games in London.
"I can't explain how it could have happened. I was always sure what supplements and medicines I was using."
Earlier this month, the International Olympic Committee said up to 31 athletes from around the world could be banned from the Rio Olympics as a result of the retests, which were conducted using the latest scientific methods.
The Russian Olympic Committee subsequently revealed that 14 of those 31 athletes were Russian.
A Russian TV report then claimed those 14 athletes included 10 medallists, among them 33-year-old Chicherova, who is planning to defend her Olympic title at the Rio Games, which begin on 5 August.
Sports minister Vitaly Mutko admitted the news did not "look good" but said the results were "not an objective picture" of Russia's doping situation.
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Russia's athletes are already banned from international competition following allegations of state-organised doping.
But in an interview with BBC sports editor Dan Roan, Mutko said he expected the ban to be lifted for Rio because it would be "useless" for the International Association of Athletics Federations (IAAF) to continue punishing them.
He also held the IAAF partly responsible for Russia's predicament, claiming it helped cover up the positive tests.
"The priority for them [IAAF] must be the development of track and field worldwide and you cannot achieve that with punishment," he said.
"It damages hugely the reputation and image of track and field. It would decrease the popularity of the sport in Russia. Kids would not want to do it."

The appeal comes on what would have been Beyake Keita Ann's 22nd birthday.
He died in hospital three weeks after the assault by a gang of men in Attock Park on 23 August.
Police said 15 men had been questioned by detectives as part of the investigation.
More on this and other Bradford stories
Officers will be staging a reconstruction of the incident.
Det Ch Insp Ian Scott said he wanted anyone who was in the park that night to come forward.
He said: "Beyake was a young man who today should have been celebrating his 22nd birthday with family and friends.
"Instead of celebrating it with him, they will be remembering his life at what is and continues to be a very sad time for them.ã€€
"We are committed to getting justice for Beyake and his family and finding out who it was that inflicted his fatal injuries."ã€€
Four London 2012 Olympic weightlifting champions have tested positive for performance-enhancing drugs.
[NEXT_CONCEPT]
Olympic medallist Anna Chicherova has vowed to clear her name after learning she is one of 14 Russian athletes to have failed a doping retest.
[NEXT_CONCEPT]
Police are asking for new information about the murder of a man who was "brutally attacked" following a row during a football match in a Bradford park.