An award-winning Guardian cartoonist is appealing to trace a missing portfolio containing a selection of his most precious works which he likens to “children”.

Andrzej Krauze was in London, returning from his studio in Chelsea to his Paddington home at around 6pm on Thursday on what was an otherwise uneventful bus journey.

But, later that evening, as he searched his home for box of drawings he thought he had carried back with him, he experienced a sudden sinking feeling.

“I was absolutely devastated,” he said, on the realisation he must have left them on the bus. The 72-year-old added: “I was 100% sure I had carried them with me. I don’t know what happened. It must have been something in my old brain.”

Cartoonist Andrzej Krauze came to Britain from Poland in 1979. Photograph: The Guardian

Krauze is now appealing for anyone for who may have stumbled across his box – an elegant, black, A3-sized cardboard portfolio – to come forward. He is uncertain whether he left it on either the first leg of his journey, the 328 from Chelsea to Notting Hill Gate, or the second – the 27 towards Paddington.

Inside the box were 12 of Krauze’s drawings from his first days at the Guardian, in the early 1990s. “This is probably what was my best period in my art,” he said. “It was very dark, very powerful. And of course, when you are young, you are more radical.”

The drawings include a image of a crumbling Russian military general, symbolising the fall of the Soviet Union, arguing with Uncle Sam in a star-spangled top hat.

One of the lost artworks that Andrzej Krauze drew for the Guardian in 1995. Photograph: The Guardian

Another depicts a snaking queue of people awaiting to enter a surgery while their doctor makes a run for it through the back door – a critique of the NHS which still resonates today. A third shows a tower block keeling over with sickness, a thermometer held in its mouth – commenting on how offices are harming our health.

Krauze’s worst fear is that somebody may have looked inside the box, seen the pieces of paper and simply put the images in a recycling bin.

He said: “You spent all your life with your drawings. They are more important than anything – more important than money. They are like children – something I made. If someone finds these drawings, I would be happy to discuss a prize.”

Also included in Krauze’s portfolio were 24 drawings which were due to be included in a calendar.

Another of the lost artworks which was due to appear in a calendar for 2020. Illustration: Andrzej Krauze/The Guardian

Krauze, who was born in Warsaw, started his career as a print cartoonist in Poland in the 1970s. He came to the UK in 1979 and was granted political asylum three years later. He won the 1996 Victoria and Albert Museum award for illustration and the 2003 United Nations Correspondents Association Ranan Lurie Political Cartoon Award.

He has published more than 5,000 drawings in the Guardian and a retrospective featuring 2,000 of his images is to go on display at an exhibition in Warsaw from 21 February next year.

If you have any information about the lost artwork, you can contact Andrzej on a.krauze47@gmail.com