Two South African women who successfully challenged a secret, multibillion-dollar nuclear deal have won a major environmental prize.

Makoma Lekalakala and Liz McDaid led a five-year court battle against South Africa's plans to build nuclear power plants with Russia.

South Africa's former President Jacob Zuma had reached an agreement with Russia's leader Vladimir Putin in 2014.

It was worth an estimated ($76bn) £54bn.

The US and South Korea had signed co-deals, in 2009 and 2010 respectively, to be involved with the project.

But last year a high court ruled the plan was unlawful and unconstitutional, agreeing with Ms Lekalakala and Ms McDaid's claims that it had been arranged without proper consultation with parliament.

The BBC's Pumza Fihlani in Johannesburg says the nuclear plans were met with huge criticism and calls for protests in some quarters, not least because finance officials, including then Finance Minister Nhlanhla Nene, insisted that South Africa could not afford the ambitious project.

It is widely believed that Mr Nene, who has now been reappointed to the role, was sacked by Mr Zuma for his refusal to rubber-stamp the deal, which opposition parties claimed would directly benefit Mr Zuma - claims the former president has denied.

Last year's landmark ruling means that any future nuclear proposals must first be passed in parliament and opened up to the public.

"Government tends to regard its citizens as sheep that will do what it says," Ms McDaid told the BBC's Newsday programme.

"When you see that something is not right you have to stand up, but often you're standing up to a bunch of bullies."

Ms Lekalakala and Ms McDaid, who were both active in the anti-apartheid struggle, represent two small human rights groups.

Ms Lekalakala works for Earthlife Africa Johannesburg (ELA) while Ms McDaid belongs to the Southern African Faith Communities' Environment Institute (SAFCEI).

"Both of us grew up in the 1970s and 1980s and we made a commitment then to challenge any injustices taking place," Ms Lekalakala told the BBC.

"We need to protect our hard-won gains and rights."

The annual Goldman environmental prize recognises "environmental heroes" and "grassroots activists" deemed to have made "significant achievements to protect the environment".

Others winners of the global award this year hail from Colombia, France, the Philippines, Vietnam and the US.