The detention of an alien who is seeking asylum can take place at any time during the asylum procedure and after the claim has been rejected at the final instance. A person can only be deprived of their liberty for a reason set out in law.
Under Ch. 10, Section 1(1) of the Aliens Act, an alien, whether an asylum seeker or irregular migrant, over the age of 18, may be detained where:
- Their identity is unclear upon entry; and
- They cannot make probable that the identity given to the authorities is correct.
Moreover, an alien may be detained:
- Where it is necessary for the carrying out of an investigation of their right to remain in Sweden;
- Where it is probable that they will be refused entry or will be expelled; or
- For the purpose of preparing or carrying out deportation.
Detention under points (2) and (3) of para 2 can only be ordered if there are some reasons to presume that the alien will abscond or will engage in criminal activities in Sweden or in any other way attempt to prevent deportation.
Detention can be applicable in so called Dublin cases, pursuant to Article 28 of the Dublin III Regulation. In Dublin cases, the Aliens Act provisions regarding detention are not applicable. The threshold for when detention can be used according to the Dublin Regulation must be met. In a 2017 ruling, the Migration Court of Appeal held, after referring preliminary questions to the CJEU on the matter, that the applicable rules on detention under the Dublin Regulation cannot be read in such a way as to set hindrances to the carrying out of transfers to other EU countries, and that the Dublin Regulation provisions on the length of detention must be read in line with the preamble of the Regulation and national law.
The courts also regularly rule on questions of detention. On 30 June 2020, the Migration Court of Appeal ruled that Article 8(3)(d) of the Reception Conditions Directive does not allow the detention of asylum seekers under the Aliens Act when they are not detained as part of a return procedure covered by the Return Directive at the time of the asylum application. This was confirmed on 25 January 2021.  Furthermore, the provisions on detention in the Aliens Act do not provide the same possibilities for detention as the Reception Conditions Directive. The Directive’s grounds for detaining an asylum seeker for the purpose of determining or confirming the applicant’s identity or nationality or for the purpose of determining the factors on which the asylum application is based can therefore not be applied when there is no support for this in the Aliens Act.
On 22 June 2022 the Migration Court of Appeal found that a decision on detention is repealed when the expulsion order is enforced. Should the person return to Sweden and be detained again, there has to be a new decision on detention, not only a new assessment of the former decision on detention.
To determine if a person is at considerable risk of absconding from a Dublin procedure there has to be an individual assessment of all circumstances from case to case. When doing such an assessment the circumstances have to be concrete and implicate a considerable risk of absconding. Examples of such concrete circumstances include if the person has used different aliases, if the person has been expressing strongly negative feelings regarding the decision on transfer according to the Dublin Regulation, if the person has stated incorrect information or if the person has withheld essential information.
 Ch. 10, Section 1(2) Aliens Act.
 Ch. 10, Section 1(3) Aliens Act.
 Migration Court of Appeal, MIG 2020:14, 30 June 2020.