An unknown substance found on board the Piper Bravo platform off the UK was legal pain medication and not illegal drugs as first suspected.
Police said on Friday they completed testing on packages found on the platform, operated by Talisman Sinopec Energy UK (TSEUK), but found nothing suspicious.
“Testing has established that the packages did not contain illegal substances but crushed medication commonly used for pain relief,” Police Scotland said.
“Police enquiries have now concluded and no further action will be taken.”
A TSEUK spokeswoman said the company had been working with the police since the discovery of the substance on Saturday 17 May.
It led to all workers on the platform being drug tested by medics.
She said: “We have now been advised by police that the substance was crushed medication commonly used for pain relief. No illegal substances of any kind were present. Police enquiries have now been concluded.
Claims cocaine had been discovered in a stairwell on the platform emerged earlier this week from offshore workers on social media.
About 150 people were on board the facility.
“TSEUK continues to operate a zero tolerance approach to illegal substances,” the company said.
Piper B is located in Block 15/17, about 193 kilometres north-east of Aberdeen.