The UK's embassies and consulates in six sub-Saharan African countries accepted more than £57,000 in corporate sponsorships for parties and drinks events from oil companies, new figures obtained through the Freedom of Information Act have revealed.

The donations, received over three years by embassies and consulates in Kenya, Uganda, Tanzania, Namibia, Malawi, and Ethiopia, are not declared on Foreign Office (FCO) annual reports or accounts, and highlight the close ties between oil companies in the region and the FCO's representatives.

The campaign group Greenpeace, which obtained the FOI data and shared the releases with BuzzFeed News, said the donations raise questions as to the revolving door and social ties between oil companies and the FCO, as well as over whether sponsoring social functions grants privileged access to support from the government department.

"This investigation into the shadowy world of corporate-sponsored parties and revolving doors raises urgent questions over the kind of influence British oil firms have over UK government officials," said Greenpeace UK executive director John Sauven.

"Many of these companies are pursuing controversial projects that could damage national parks, put endangered wildlife at risk, and will certainly drive more climate change in African countries that are already vulnerable.

"The UK government can’t have its cake and eat it. If Britain is serious about honouring the Paris climate deal, its government officials must stop acting like the oil industry's lobbying arm."

The FCO began accepting contributions towards embassy events such as the Queen's birthday celebrations as a cost-saving measure, BuzzFeed News understands, and as part of the department's role in promoting business interests overseas.

Embassies are only required to disclose the contributions in the Foreign Office's annual accounts if an individual contribution exceeds £5,000. If a company makes multiple contributions – whether to the same embassy or multiple ones – totalling above this figure, these do not appear in the accounts.

The £57,000 total in the FOI figures includes £12,500 from Shell subsidiaries, and around £8,900 from Tullow Oil.

Correspondence between FCO officials and oil executives shows warm relations between the two, and that business is discussed at the parties thrown by the companies and executives.

One such piece of mail was sent by an UK Trade and Investment official in Uganda to a Tullow executive. “Dear Dean, as briefly discussed on Friday (during the Tullow end of year party – which was amazing!) we write to request a meeting with you," it begins.