However, the company in a statement said only one person was killed.
Tragedy has struck at Seplat Energy company with at least one person killed.
Sources told SaharaReporters that five Nigerian oil workers and one British expatriate lost their lives while many others are still missing following an accident at the company's 'majestic rig' near Ovhor Oilfield, in the Sapele Local Government Area of Delta State.
However, the company in a statement said only one person was killed.
SaharaReporters gathered that the accident which occurred in the early hours of Tuesday at the newly acquired 'majestic rig', operated by SEPLAT/NNPCL joint venture had 96 crew members and about six bodies have been recovered so far.
Confirming the incident to SaharaReporters, a senior management officer of the company who spoke on condition of anonymity as he was not authorised to speak with journalists on the issue, said the tragic incident led to panic in the company.
He added that the management of the company was on top of the situation and that all efforts were in top gear to find the missing persons.
"I can tell authoritatively tell you that some bodies have been recovered and most of the workers are very safe and getting medical attention.
"However, very painful, we have lost six personnel of the company in the accident. As of 9:00 pm, six workers of the company are still missing with efforts in place to find them. Among those we lost are a Briton and five Nigerians," one of the sources said.
A statement issued on Tuesday evening which was signed on behalf of the management of Seplat Energy Company by its Chief Executive Officer, Roger Brown and obtained by SaharaReporters, confirmed the tragic accident.
It said out of the 96 crew members on the rig, 92 were safe.
It added that one fatality occurred during the incident and that three other rig personnel were still missing.
"Seplat Energy regrets to announce a serious incident on the Depthwise swamp drilling rig "Majestic" in the early hours of this morning. Seplat as the operator of the SEPLAT/NNPCL joint venture contracted the rig.
"It was in-transit to its planned drilling location at Ovhor in Delta State when it capsized. 92 of the 96-member crew are accounted for and safe. However, tragically one fatality occurred during the incident, while three other rig personnel are still missing.
"Our thoughts and prayers are with the families and friends of the crew member who sadly lost his life and the three crew members who are still missing at the time of this report.
"Our emergency response and rescue efforts working alongside the rig owner and the authorities have been activated and are onsite. Our utmost priority will continue to be the safety and wellbeing of all the affected personnel and their families. We will provide further details as our understanding of the incident develops. A detailed investigation into the cause of the accident will follow," the Chief Executive Officer stated.