Republican presidential nominee Donald Trump's appearance on Reddit for a Q&A session ended with the billionaire answering just a handful of questions in a chat that was controlled by staunchly pro-Trump moderators.

Many users took to Twitter to complain that their questions had been deleted and that they had been banned from viewing the thread.

The popular content aggregation site regularly hosts 'Ask Me Anything' (AMA) sessions with celebrities, but Trump's much-hyped appearance (hosted on subreddit r/The_Donald) saw him respond to users just 12 times.

AMAs are an increasingly-popular way for candidates to open dialogue with younger voters - and have been used both in Australia and abroad by many well-known politicians; including Scott Ludlam, Rand Paul, Bernie Sanders and current United States President, Barack Obama.