The days of finding random pages of porn magazines in park bushes are almost over. Like Playboy, Penthouse has decided to focus its mucky mind on the internet instead.

But while Playboy is to continue to publish a print magazine after March, except without nude photography, Penthouse is shutting its physical edition entirely. After 51 years it will no longer have a mag on the shelves.

Instead, there will be a digital edition only, with subscribers of the print edition being switched to the company's website.

READ: Free porn on the net to blame for Playboy dropping nudes

The print magazine will continue to appear for a while as the move to digital-only takes place. No date has been set as to when that will complete but it is thought to be soon.

"This will be a new way for its readers to experience the world's best adult magazine," said publisher General Media Communications.

"Reimagined for the preferred consumption of content today by consumers, the digital version of Penthouse Magazine will combine and convert everything readers know and love about the print magazine experience to the power of a digital experience."

Both Penthouse and Playboy have been at threat due to the tsunami of free internet pornography. The former was bought out of bankruptcy in 2004 by FriendFinder Networks, but is not considered to have made money for a while.