Pornographic images have started to appear on the side of balloons in Super Mario Odyssey, a video game popular with youngsters.

Hackers have found a way to attach the adult images to the balloons, which appear as part of an online competitive challenge in the Nintendo Switch title.

Experts believe they have gained access to a piece of software used by game creators, which has unlocked options that are usually hidden from public view.

They have used this tool to override the cartoon avatars that normally appear on the balloons, and instead inserted their own smutty icons.

Social media users were the first to raise the alarm about the sick prank, warning parents to be on the look out for the rogue objects.

Nintendo has yet to issue a statement on the incident.

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Pornographic images have begun to appear on balloons in Super Mario Odyssey, a game popular with youngsters. Hackers appear to have found a way to append the adult photographs to the inflatables (pictured right)

Among the first to spot the inappropriate content was Reddit user ewasion, who noticed that the family-friendly avatars usually present on the balloons had been replaced with something much more inappropriate.

Writing on the social news site, he said: 'The picture was changed several times over the course of my time patrolling, each picture being pornographic content.

'There are multiple of these balloons all being made by the same user.

'This is obviously intentional, and made to upset children.

'While we wait for Nintendo to offer better parental controls, I am taking my child's switch offline and I encourage others to do so with me.'

Social media users were the first to raise the alarm about the sick prank. Reddit user ewasion said: 'While we wait for Nintendo to offer better parental controls, I am taking my child's switch offline and I encourage others to do so with me'

HOW HAVE HACKERS PUT PORN INTO SUPER MARIO ODYSSEY ON THE NINTENDO SWITCH? In June 2018, social media users raised the alarm about a sick prank, in which hackers were attaching adult images to balloons in the Nintendo Switch game Mario's Odyssey. The issue appears to be limited to the title's Luigi's Balloon World mode, a balloon hunting mini-game that involves searching for objects hidden by other online players. A cartoon picture of the player who hid the balloon, known as Miis, or characters from Nintendo's roster of titles are normally displayed on the side. Hackers found a way to insert their own images, resulting in the lewd images spotted by gamers. Experts believe this is related to the spread of a piece of software called DevMenu, a tool designed for use by developers of games and other software for the Switch. It appears to have fallen into the hands of the modification and hacking community, with seemingly smutty results. By using DevMenu, hackers can gain access to a range of functions usually reserved for programmers. This lets them unlock options within games that are normally protected. Rather than choosing from the existing range of family-friendly avatars, these users appear to have created their own adult-themed icons. These then began to appear on balloons hidden in Luigi's Balloon World. Advertisement

The issue appears to be limited to the online challenge Luigi's Balloon World, a balloon hunting mini-game that involves searching for objects hidden by other online players.

Players can typically only pick between a cartoon representation of themselves, known as a Mii, or a character from another Nintendo title.

However, hackers appear to have found a way to insert their own images into the game to use as an avatat – resulting in some choosing to upload pornography.

Experts believe this is related to the spread of a piece of software called DevMenu.

The issue appears to be limited to the title's Luigi's Balloon World mode, a balloon hunting mini-game that involves searching for objects hidden by other online players (pictured)

A cartoon picture of the player who hid the balloon, known as a Mii, or characters from Nintendo's roster of titles are normally displayed on the side. Hackers appear to have found a way to insert their own images, resulting in the lewd images spotted by gamers.

This is a tool designed for use by Switch developers.

However, it has fallen into the hands of the modification and hacking community, with seemingly smutty results.

By using DevMenu, hackers can gain access to a range of functions usually reserved for programmers.

This lets them unlock options within games that are normally protected.

Rather than choosing from the existing range of family-friendly avatars, users are creating their own icons, including some with an adult-theme.

It may lead to further such hacks on Nintendo titles in the future.

MailOnline has approached Nintendo for comment on the pornographic images.

Experts believe this is related to the spread of a piece of software called DevMenu (pictured), an official Nintendo tool designed for use by developers of games and other software for the Switch. It appears to have fallen into the hands of the hacking community