Media regulator Ofcom is to investigate TalkTalk following reports the broadband provider has breached regulations relating to silent calls.
Earlier this year, new rules were introduced to combat the misuse of automated dialling equipment, with fines of up to £2 million now possible for repeat offenders.
Ofcom said it has "reasonable grounds for believing that TalkTalk persistently misused an electronic communications network", reports ComputerActive.
A TalkTalk spokesperson said the firm had already taken steps to improve its performance in this area by changing its advertising practices.
They explained that in February and March 2011, a contracted partner was responsible for a number of abandoned marketing calls being made.
And a sales agency working for TalkTalk's business-to-business division was also found to have made excessive abandoned calls, the spokesperson added.
"[TalkTalk] demands high standards from the companies it works with and closely monitors their performance," they said.
"[We] no longer work with these sales agencies and, if Ofcom imposes a financial penalty, we will recover this sum from the third party responsible."