Russias seize Spanish ships

[Spearfish]

In 1938 the Soviet Union seized between six and eight Spanish Republican merchant ships.
Does anyone know exactly when this took place and why?

[Ironmachine]

AFAIK it began earlier, already in 1937, and the ships seized were nine (in the following list, first is the name of the ship, then the shipping company in brackets, and finally the Soviet port in which the ship was seized):
Cabo Quilates, (Ibarra), Murmansk
Marzo, (Bilbao), Murmansk
Cabo San Agustín, (Ibarra), Feodosiya
Ciudad de Ibiza, (Transmediterránea), Odessa
Ciudad de Tarragona, (Transmediterránea), Odessa
Isla de Gran Canaria, (Transmediterránea), Odessa
Inocencio Figaredo, (Gijón), Odessa
Juan Sebastián Elcano, (Trasatlántica), Odessa
Mar Blanco, (Marítima del Nervión), Odessa
It seems that no one in Spain was ever aware of the real reasons the Soviets had to seize the ships. They simply choosed some of the Spanish ships that arrived to Soviet ports and, alleging errors in documentation and permissions, refused to let them sail back to Spain. Perhaps some Soviet sources can reveal the real reasons to choose those ships and seize them.
Hope that helps.
Regards.

[Spearfish]

As always Ironmachine very many thanks.
I had not previously been aware of how the ships were seized and on what grounds.
I wonder whether one reason might be they were seized for financial reasons given that most of the Spanish gold had been 'spent' on Soviet war material by 1938.
Regards

[Ironmachine]

Don't think so. As I wrote, this began already early in 1937, when the gold had not been 'spent' by any measure. Not to mention that Soviet gross overprizing was the main cause of the gold been 'spent'.