Port Adelaide player Sam Powell-Pepper has made headlines once again and has been forced to publicly apologise for releasing a "private image" via his social media account.

It is the second time this year that the midfielder has been caught up in controversy away from the football field.

He was suspended by the AFL in April after he was found to have inappropriately touched a woman at an Adelaide bar while he was drunk. The incident occurred following the Power's win over Brisbane.

But in the latest incident, he posted a "private image" on his Instagram account — which was quickly removed — that shows a man lying on a bed in his underwear, with a woman lying on his thigh.

Powell-Pepper was quick to sound out an apology via his Instagram account, which has more than 20,000 followers.

He released a statement on his social media account shortly after the post apologising for the accident.

"I just want to apologise for an image I posted earlier today of me and my girlfriend," his post said.

"I posted the image by accident and immediately removed it once I realised.

"It's a private image that was not intended to be shared publicly.

"Apologies if I have offended anybody."

Powell-Pepper released an apology shortly after on his Instagram account. ( Instagram: sampowellpepper_ )

The AFL announced it would be investigating the incident via a statement, saying it was "disappointed" to see the image on social media.

"The AFL is disappointed to see an image like this shared on social media. We request that the person who is identifiable be protected and respected by the media," the statement read.

"The AFL Integrity Unit and the GM Social Policy is assessing the photo and its distribution. The AFL has spoken with the club.

"No further comment shall be made at this stage."

The Port Adelaide Football Club also released a statement on Friday afternoon stating it was aware of the image and was comfortable that it was "unintentional".

"Port Adelaide Football Club is aware of an image posted on Sam Powell-Pepper's Instagram account earlier today," the statement said.

"The club has spoken to all parties and is comfortable the posting of this image by Sam of he and his girlfriend on this public forum was unintentional.

"Sam has apologised and the club has fully accepted his apology. The club asks media to respect the privacy of Sam and his girlfriend regarding this matter."