Emergency services were alerted to concern for the 77-year-old man near Strathtay, Perthshire, at around 5.30pm on Sunday.

Police Scotland said the search resumed on Monday morning.

In an update in the afternoon, a force spokesperson said the man was "swept" into the river.

They said a multi-agency response was set up after the alarm was raised, adding: "Conditions on the River Tay remain challenging and specialist resources are being used, including drones and the Police Scotland helicopter, to find the missing man."

Flood warnings currently remain in place following a weekend of extreme rainfall that saw disruption across Scotland's roads and railways.

The Met Office had issued an amber weather warning across Angus, Perth and Kinross, Aberdeenshire, Moray and the Highlands.

Read more: Latest weather forecast

All heavy rain warnings have since been lifted, but a yellow alert over the western part of the country has been issued for Tuesday.

The relentless rainfall over the weekend led to road closures and train cancellations.

Landslides blocked some roads in the west of Scotland, with 10 drivers being rescued by helicopter after becoming trapped on the A83 near Inverary in Argyll and Bute.

Another four were airlifted in Kilmartin.

Road maintenance and management firm Bear Scotland said around 2,000 tonnes of debris had fallen onto the A83.

In an update on Monday morning, Bear NW Trunk Roads said the Inverary-Tarbet road remains closed.

A spokesperson added: "Our teams worked incredibly hard over the weekend and the clear-up continues".

ScotRail said disruption caused by flooding will continue into Monday for some routes, with services between Edinburgh/Glasgow Queen Street and Inverness, and Glasgow Queen Street to Aberdeen/Dundee/Perth and Arbroath unable to run.

The challenges posed by the flooding has been compared to those faced during the Beast from the East period of cold weather in 2018.

Stein Connelly, head of transport resilience at Transport Scotland, said: "It's been an extremely challenging 72 hours, with perhaps some of most difficult conditions we've experienced since the Beast from the East.

"In terms of Argyll, the area around the A83 Rest and Be Thankful saw a month's worth of rainfall, around 160mm, fall over 36 hours."

Two severe flood warnings remain in place in Aviemore/Dalfaber in the Highlands and in Perth.

The Scottish Environment Protection Agency (SEPA) has also issued 37 flood warnings and five flood alerts around the country.

Ruth Ellis, SEPA flood duty manager, said: "Across many areas of the country there is still some deep-standing water and it's really important people understand the danger. Hazards can be hidden, so please don't walk or drive into flood water.

"Remember that not only is flood water likely to be dirty, 30cm of fast-flowing water can move an average family-sized car, and just 15cm of fast-flowing water could be enough to knock you off your feet."