Authorities demand major US internet companies prove their speed claims

New York attorney general's office tells Time Warner, Verizon and Cablevision it is concerned their 'fast lanes' and premium services may be false advertising

A group of major US internet providers have been told to prove their "fast lanes" and premium services are any quicker than ordinary internet access.

The office of New York's attorney general has written to Time Warner, Verizon and Cablevision raising concerns that subscribers might not be getting the speeds advertised. Senior enforcement counsel Tim Wu requested detailed information by 8 November. He warned records could be subpoenaed and legal action taken to stop any deceptive business practices.