Regulators are approaching the Conservative Party following accusations that it broke the law during the General Election campaign.
An investigation by Channel 4 claimed the party used communication firm Blue Telecoms to conduct marketing work from a Neath call centre ahead of the election on 8 June.
The Information Commissioners Officer (ICO), which is charged with protecting the UK public's personal data, has said it will be talking to the party about its marketing campaign.
Channel 4 news suggested that the Blue Telecoms team was engaging in paid canvassing, which is banned under electoral law.
Blue Telecoms was also engaged by the Conservative party during the 2015 election.
An ICO spokesperson said: "The Information Commissioner reminded campaigners from political parties of their obligations around direct marketing at the beginning of the election campaign.
"Where we find they haven't followed the law, we will act."
Ahead of the General Election, the ICO invited the political parties to attend briefings on the use of personal data in political campaigning. The body felt compelled to do so due to a rise in complaints about parties using marketing surveys to promote political parties and candidates.
People have also complained to the ICO about their information being passed on to other organisations.
A Conservative spokesman said: “Political parties of all colours pay for market research and direct marketing calls. All the scripts supplied by the party for these calls are compliant with data protection and information law.”