The couple arrested in a dawn raid on Tuesday are both Russian citizens.

It indicates that they - if they committed the crimes they are accused of - worked on behalf of Russia.

That assessment is made by Tony Ingesson, assistant lecturer in intelligence analysis at Lund University.

- The most likely is Russia, but of course I can't say that with certainty.

It doesn't have to be automatically, he says.

That civilians of Russian origin are recruited as spies is not that common, says Ingesson.

- It's interesting, because they don't have the protection you have when you have diplomatic cover.

It is not the most typical, otherwise you usually recruit a Swedish citizen or a person who has no obvious connection to Russia.

Säpo: Russia behind the majority of the cases

In recent years, there have been several espionage cases where Russian involvement has been established or suspected.

Among other things, the man convicted of spying against Scania and Volvo, and the two brothers who are suspected of having spied on behalf of Russia.

According to a report from the Total Defense Research Institute, Russia is responsible for the lion's share of the espionage cases discovered in Europe in recent years.

The security police have also identified Russia as the dominant intelligence threat against Sweden.

One of the goals of the Russian operations is to "acquire military and civilian technology," according to an intelligence report.

In addition, the Russian intelligence officers are said to collect information about Sweden's defense, politics and economy, and as a rule work undercover as diplomats at the Russian embassy.

It can mean "meetings with business contacts".

It appears from the documents at the district court that the suspected crime must have consisted, among other things, in meetings with "business contacts or suppliers".

- It sounds like they either tried to extract information from these people or tried to recruit them, says Ingesson.

The purpose of such contacts can be so-called industrial espionage, says Tony Ingesson, but it can also involve, for example, trying to get information about the Armed Forces via its subcontractors.

Both suspects deny any crime, according to their respective defenders.