UEFA has issued a warning about the rise of multi-club investment, which could potentially pose a threat to the integrity of European club competitions.

The warning comes as a result of a sharp increase in the number of clubs under cross-investment influence, with investors showing a growing interest in clubs with access to the biggest and most stable sources of income.

According to a recent study, the majority of multi-club structures involve at least one non-European club, with almost half of the clubs on the map sharing an investment relationship with a football club outside Europe.

This percentage is rising fast, with many investors in North American clubs also taking stakes in European clubs.

However, the rise of multi-club investment has the potential to see two clubs with the same owner or investor facing each other on the pitch, posing a material threat to the integrity of European club competitions.

Approximately two-thirds of all national associations have rules directly limiting or restricting multi-club ownership at domestic level, with some countries imposing more onerous requirements than others.

A growing number of countries have implemented checks and tests that new owners have to pass before taking control of a football club, but UEFA is urging caution in the rise of multi-club investment.

While investors may see benefits in investing in two clubs before acquiring any more, UEFA is warning that the potential risks to the integrity of European club competitions cannot be ignored.