Nintendo and its partner, The Pokémon Company, have filed a legal case against the maker of the hit survival adventure game Palworld over alleged patent infringement.

Palworld quickly earned the nickname 'Pokémon with guns' when its first trailer was unveiled in 2021.

Just days after the game's release in January this year, The Pokémon Company said it would investigate the copycat claims.

Palworld's developer, Pocketpair Inc, acknowledged the lawsuit in a statement on Thursday and apologized to fans for 'any worry or discomfort' caused.

Like the popular franchise of Pokémon video games, it also centers around collecting strange creatures with different powers.

Pocketpair's website describes the game as seamlessly integrating 'elements of battle, monster-capturing, training, and base-building.

' Players, known as 'pal-tamers', travel around a large map battling human foes and creatures known as 'pals' which can be captured and recruited.

The monsters can either fight alongside the player in battles or be put to work at a base, crafting supplies and items for use in the field.

The Pokémon Company said at the time it would take 'appropriate action' if it found its copyright had been breached.

Pocketpair said on Thursday it would begin taking action on and investigating The Pokémon Company's claims.

It added that it was 'truly unfortunate' that it would need to allocate time and resources to the lawsuit, rather than game development - highlighting its status as a smaller, indie developer.

'However, we will do our utmost for our fans, and to ensure that indie game developers are not hindered or discouraged from pursuing their creative ideas,' it said.

Philip Morris International bought Vectura Group just three years ago in a deal worth more than £1bn.