The Scots actor, who plays fan favourite DI Steve Arnott, joined the cast on stage as the cop drama scooped a Special Recognition Award and another for Best Returning Drama.
And fans of the hit BBC show were left speculating after Martin teased he could reprise his starring role once again.
The sixth series saw the Jed Mercurio hit come to a conclusion earlier this year.
Speaking on stage, Martin said: “This means so much, like we started as a wee show on Wednesday night on BBC Two and now we’re the biggest drama on TV and it’s all because of the fans – we owe everything to you.
“We genuinely don’t take this for granted and who knows, maybe we’ll be back again.”
Co-star Adrian Dunbar, who plays Superintendent Ted Hastings, also joined in as he appeared to hint at a new series.
Speaking remotely due to filming commitments, Adrian added: “Thanks so much for the NTAs for this, absolutely over the moon for this.
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“Most of all the great British public who so overwhelmingly supported us. And as Martin says, who knows? We might be back?”
The rumour mill has been going wild since Line of Duty appeared to come to a dramatic end in May this year.
Millions tuned into the final episode of the series, which seemed to show AC-12 succeed in their mission to track down the illusive ‘H’ – who was also known as the “Fourth Man”.
Martin Compston has been praised throughout the show, which saw him adopt a cockney accent over his native Greenock one.
And it has paid off for the 38-year-old, who has now won multiple awards over the past week.
The Scot scooped the gong for Best Actor at the TV Choice Awards earlier this week for his role as DI Steve Arnott.
He also showed flashes of his ex-footballer-self when he took home a winners medal at Saturday’s Soccer Aid tournament.
Martin’s World XI side managed to defeat a star-studded England team 3-0 in Manchester over the weekend.