SINGAPORE - Telco M1 has apologised for a technical fault that caused calls to its customer service hotline 1627 to be diverted to the Singapore Police Force's emergency hotline on Friday.

In a Facebook post at around 3pm, M1 apologised for the inconvenience caused. "Some calls to our hotline were inadvertently diverted to 999," it wrote.

In a statement late Friday, M1 said only customers in the eastern and Central Business District of Singapore who accessed the Internet between noon and 1.30pm were affected.

A file was configured wrongly when the telco was tweaking its 4G voice's emergency call feature, resulting in its hotline being wrongly mapped to the local emergency number.

Customers were advised to reboot their mobile phones to reset their devices, which could have downloaded the erroneous file.

The problem, which lasted for about two hours, was rectified at around 1.30pm.

"We sincerely apologise to the Singapore Police Force and our customers for the inconvenience caused," the statement read.

The Infocomm Development Authority (IDA) said it is also currently investigating the matter.