Organisers of the Tour of Poland have neutralised and shortened the distance of Tuesday's scheduled 173km fourth stage following the death of Belgian rider Bjorg Lambrecht.

"The race organisers, the jury and the teams have made a decision to neutralise the 4th stage of the Tour de Pologne to pay our respects to Bjorg," said a statement on the Tour website.

"The stage route has been reduced to 133.7 km and the final laps have been cut to 1," the statement added.

There were emotional scenes at the start of the day's stage in the southern city of Jaworzno as Lambrecht's fellow Lott-Soudal riders wore black armbands and took part in a minute's silence.

They then repeated the hommage and stopped cycling at the same distance where Lambrecht had crashed a day earlier.

The 22-year-old lost control of his bike following rain and collided with a concrete bridge over a ditch around 30 kilometres into the third stage on Monday.

His parents had seen him off at Monday's start and where waiting for his arrival at the finish line, race organisers said

He was resuscitated on the spot, then taken in a critical condition to a hospital Rybnik, where he died on the operating table.

The city's public prosecutor have opened an investigation into the causes of the incident.

Lambrecht was one of Belgium's great hopes for the future of cycling. He won the Under 23 Liege-Bastogne-Liege and finished second in the Tour de l'Avenir in 2017 behind this year's Tour de France winner Egan Bernal before turning professional last year with Lotto-Soudal.

This year he placed 12th at the Criterium du Dauphine, winning the best young rider category, fourth in La Fleche Wallonne and sixth at the Amstel Gold.

- 'Rest In Peace Bjorg' -

Lambrecht's death brought a flurry of tributes across social media from all corners of the cycling world.

"Such an incredibly sad day here in Poland and across the cycling world," tweeted Mark Cavendish who finished sixth in Monday's stage.

"To the family, friends and teammates of @bjorg_lambrecht, all our thoughts and sympathies are with you. Rest In Peace Bjorg. May your star continue to shine as brightly as it did in cycling."

Alejandro Valverde, the world road race champion in 2018, echoed Cavendish's comments.

"Deeply sorry for the loss of Bjorg Lambrecht, a cyclist who had demonstrated a lot in a few years," the Spaniard tweeted.

Lambrecht is the third professional cyclist to die during a race since the beginning of 2018.

Belgian rider Michael Goolaerts, 23, suffered a heart attack during last year's Paris-Roubaix one-day classic as did Dutch 27-year-old Robbert de Greef in April after competing in the Omloop van de Braakman.

Three years ago, another young rider from Belgium, 22-year-old Daan Myngheer, died in hospital two days after suffering a cardiac arrest on the Criterium International in Corsica.