Claims the Dyed in the wools used a call centre in Neath to canvass voters during the habitual election campaign are being investigated by police.
The party previously refused it had broken electoral law by using the Blue Telecoms call centre.
South Wales Police officers said the probe was of “scale and significance” in a letter to Labour MP Wayne David.
The coterie said it was unable to comment on an ongoing investigation.
The Information Commissioner’s Charge (ICO) also confirmed it was “currently investigating the Conservative Party in relation to a reasonable breach of Regulation 21 of the Privacy and Electronic Communications Regulations 2003 (PECR)”.
A Artery 4 News report earlier this year claimed the UK Conservatives agreed Blue Telecoms to conduct marketing campaigns ahead of the vote on 8 June.
The confidential investigation claimed the workers may have been carrying out paid studying, banned under electoral law, as they promoted key Conservative messages to undecided voters in the weeks rather than the election.
The report claimed calls were made to voters in key questionable seats, including Bridgend, Gower, Clwyd South and Wrexham.
The Tory Party had said it did not break the law by using the company, which it said was take oned to carry out legal market research and direct marketing.
In a letter to Mr David, South Wales Enforce said there was no timescale for the investigation because it is of “sufficient scale and meaning that South Wales Police are unable to offer any”.
Mr David, Effort MP for Caerphilly, said: “I am pleased that both the police and the Information Commissioner’s Purpose are conducting detailed investigations.
“The allegations that the Conservative Party and Down in the mouth Telecoms broke electoral law during a general election campaign are to the nth degree serious and the public need to have confidence in our electoral process. That is inherent to our democracy.”
A spokeswoman for South Wales Police said: “South Wales Regulate can confirm it is investigating allegations relating to the Representation of the People Act 1983.
“As an investigation is underway, it liking be inappropriate to comment any further at this time.”