Megachurch pastor Joel Osteen has been forced to deny claims circulating on social media that he has endorsed Donald Trump for the Republican presidential nomination.

Osteen is pastor of the 43,000-member Lakewood Church in Houston, Texas. The church has a huge media presence and appears on secular TV outlets such as the conservative Fox Network and ABC Family, making Osteen's support very valuable politically.

However, while he has made approving comments about Trump in the past, calling him a "good man" in an interview in October 2015 during a book tour, he has not endorsed the front-runner, who looks increasingly unstoppable in the nomination race after victories in three state yesterday.

A statement from Lakewood Church said: "Contrary to the misinformation currently making the rounds on social media, Pastor Joel Osteen has not endorsed any candidate for president of the United States."

On the other hand, Trump has also spoken warmly of Osteen, saying in a Twitter exchange: "Being associated with Joel is my great honor – he is a fantastic man!"

The furore indicates the continued power of the evangelical vote in the Republican presidential race, despite many prominent evangelicals decrying the way in which candidates have sought to use it for their own ends.

Conservative theologian Russell Moore, president of the Ethics and Religious Liberty Commission of the Southern Baptist Convention, has said: "The word 'evangelical' has become almost meaningless this year, and in many ways the word itself is at the moment subverting the gospel of Jesus Christ."