A watchdog has said that British aid money could be helping traffickers bringing migrants to Britain from Libyan detention centres.

A report from the Independent Commission for Aid Impact found that almost £9m in UK aid money, which is spent on the Libyan Coastguard and detention centres, could be increasing the number of people detained in Libya who are then trafficked to Europe.

Aid money helps the coastguard pick up more migrants from the Libyan coast and bring them to detention centres.

Libyan officials are suspected of trafficking migrants from the same detention centres, raising the risk that British aid money is providing them with a ready supply of migrants to be smuggled to Europe.

The report also raised concerns about the conditions in the centres. It argues that migrants face "extortion" as well as coming into contact with people traffickers.

Support for the coastguard means that more refugees are picked up and sent back to "a system that leads to indiscriminate and indefinite detention and denies refugees their right to asylum".

Some migrants are also sent back to their countries of origin under "voluntary repatriation", a process which the report says "is not truly voluntary" if the alternative is detention.