A student has proven himself to be just about the best grandson ever after surprising his grandparents with a cheque which will allow them to finally pay off their mortgage.

Stefun Darts, a full-time student at San Jacinto College in Texas, the US, posted a video clip online of himself handing over the $15,000 (£10,540) gift to his grandmother and grandfather who have been making monthly payments on their house for over 20 years.

According to local news site KHOU.com, the pair still had four years to go until 24-year-old Darts - who also has a full-time job as well as running two small non-profits - stepped in to lend a helping hand.

The site also reports that Darts had been eating microwave pizza and avoiding going out with his friends so that he could save up the surprise amount.

In a message posted online to both his grandparents, Darts said he “promised God” while in the second grade that he would pay off their house and help them to retire, adding it was a promise he “would never break.”

He continued: “The best and most beautiful things in the world cannot be seen, nor touched...but are felt by the heart.

“Even with this, I could never repay you for what you’ve done for me. I sacrificed my teenage and early adulthood of not having fun for this moment. I couldn’t stand you going to work at night, some nights I didn’t even sleep knowing it shouldn’t be like this.

“Never have I wrote a check wanting this to be the first one. To all my friends that stood by me over these last six years, I appreciate you.”